The Data Base Maintenance Center (DBMC) stores and maintains clinical data for the Stroke and Traumatic Coma Data Banks. The objectives of the Data Bank Projects are to efficiently collect, store, retrieve and manage clinical data in order to carry out research on cerebrovascular disease and to identify the course of traumatic coma and patterns of survival and recovery. The DBMC receives the data via nighttime transmission from the data bank clinical centers. The maintenance center provides an existing, flexible computer system with a set of programs that examines trends and relationships among data items. Descriptive statistical programs such as frequency counts, scatter plots and cross-tabulations are provided as part of the software package. In addition, the DBMC provides utility programs for creation of files to interface with standard statistical packages such as the Statistical Analysis System (SAS) and the Statistical Package for the Social Sciences (SPSS). The DBMC provides all program documentation and site training at the clinical centers on the use of the system and has staff available on a daily basis for any assistance needed by the clinical centers or OBFS.